Minecraft!!!
Update, November 2014: These days, I’m hosting my own vanilla minecraft server on Linode, using MCMyAdmin for a web interface. I finally did it. I broke down and rented a Minecraft server. Previously, I had hosted a Minecraft server pretty successfully on my personal web server. The problem became two-fold: it was a huge time-sink, as updating all the plugins that I was running took a long time at each release....